The film begins when a boy named Telly and an unnamed 12-year-old girl are making out on a bed. With no adults around, Telly, who is a few years older, persuades the girl, who is a virgin, to have sex with him. Afterwards, he meets with his best friend, Casper, and they talk about his sexual experience. Telly has taken to only having sex with virgins.
They go inside a local store, where Casper shoplifts a 40 oz. bottle of malt liquor as Telly distracts the cashier. Looking for drugs, food, and a place to hang out, they head to their friend Paul’s apartment, though they express dislike of him on the way there. They arrive at Paul’s house, join the other boys in boasting about their sexual prowess (as well as their nonchalant attitudes to both unprotected sex and diseases), and smoke marijuana while watching a skating video. Casper inhales nitrous oxide out of balloons, which Telly considers dangerous.
Across the city, a group of girls, among them Ruby and Jennie, are talking about sex, with their attitudes contradicting the boys on many topics, particularly oral sex and the significance of the boys to whom they lost their virginities. Ruby and Jennie mention that they were recently tested for STDs at Ruby’s request, though Jennie only got tested to keep Ruby company. Ruby’s test is negative, though she has had multiple sexual encounters, many of them unprotected sex.
Jennie tests positive for HIV. She says she has had sex only once, with Telly. Jennie spends the rest of the day trying to find Telly, to prevent him from passing it on. Telly and Casper walk to Telly’s house and steal money from Telly’s mother, who is preoccupied with taking care of her new baby.
They go to Washington Square Park and buy a dime bag of marijuana from a Rastafari. They then meet up with a few friends to talk and smoke, one of whom gives a blunt-rolling tutorial. As they do, Casper and many others taunt a homosexual couple passing through the park. On the side, Telly briefly talks to Misha, a girl who strongly dislikes Casper, calling him a jerk.
As Casper rides on a skateboard, he carelessly bumps into a man, who furiously threatens him. He pushes Casper, but is struck in the back of the head with a skateboard by Casper’s friend Harold, causing him to collapse. A number of other skaters join in, beating, stomping, and hitting the man with their skateboards until he is rendered unconscious by a final blow to the head by Casper.
While discussing whether or not they killed the man at the park, Telly and some of the group pick up a 13-year-old girl named Darcy, the virginal younger sister of an acquaintance, whom Telly wants to have sex with. He convinces her to go with them to a pool. The other girls engage in kissing and flirtation, but Darcy is restrained. Telly and the group go to an unsupervised party at the house of another friend, Steven.
Meanwhile, Jennie makes her way to Washington Square Park. Here, she talks to Misha, who tells her about Telly’s possible whereabouts. Jennie goes to a rave club called “NASA” trying to find Telly. She runs into Fidget, a raver boy, who shoves a pill into her mouth, which he says is supposed to make “Special K look weak”. It turns out to be a depressant. The pill kicks in and Jennie eventually finds out that Telly is at the party at Steven’s house.
Jennie arrives at the party only to learn she is too late, as she discovers Telly having sex with Darcy. Emotionally drained and the drug still affecting her, Jennie cries and passes out on a couch among the other sleeping partygoers. Casper rapes Jennie as she sleeps, inadvertently exposing himself to HIV. As morning turns to day, a voice-over by Telly explains how sex is the only worthwhile thing in his life. The next morning, Casper wakes up and says “Jesus Christ, what happened?”